The turbo machine according to the invention can be of any type, for instance a steam turbine, a gas turbine or a turbo compressor. Basically the turbo machine consists of two main parts, a rotor and a casing, wherein the rotor and the casing have a rotor sealing in the area, where the rotor protrudes out of the casing. Due to the relative motion with the rotational speed of the rotor to the stator one major problem of any design is to seal off the necessary clearance between the rotor and the stator preferably with contact. Several approaches deal with the lowering of the leakage through this circumferential gap. In most cases a process medium is used to prevent leakage fluid exiting the casing. In any case, the sealing of the casing and the necessary sealing fluid supply diminishes the efficiency of the respective turbo machinery. Hence, steady effort is spend to reduce the amount of sealing fluid, which commonly results in the smallest radial gap between the rotor and the stator possible. Especially, in the field of gas turbines abradable seals are used so that the rotor machines its radial clearance during the first start itself. The second design approach which often is applied in conjunction with the abradable sealing makes use of a special geometry of at least one seal surface. Often circumferential seal strips are inserted in the rotor and the corresponding stator surface facing the seal strips has a special topological pattern, for instance a honeycomb shape also called honeycomb sealing. The honeycomb seals are permanently attached for example to the stator by welding and/or brazing methods due to reasons of mechanical integrity as well as different degrees of necessary heat resistance and thermal behavior. Often the stator component of the honeycomb seal is attached to a segmented ring also called segment.
During operation of a gas turbine or any other turbo machine, degradation of the honeycomb seal occurs and also unplanned damage can happen for example by foreign objects in the gas stream respectively steam flow. Also after several start-ups under differing starting conditions the honeycomb seals are partially worn away and the overall thermal efficiency decreases. Depending on the degree of efficiency loss it becomes economically feasible to repair the seals. Due to the complexity of honeycomb seals the replacement of these parts is usually expensive and the expected down time is also enlarged so that some turbo machines are operated with wasted seals since a repair would be less expensive than the operation with lowered efficiency. Especially in the context of low carbon dioxide emission these circumstances become unacceptable.
US 2004/265120 A1 and EP-A-1 416063 disclose a method of the incipiently mentioned type. US 2006/042083 discloses an apparatus according to the preamble of the claims.